The present invention refers to an apparatus for excavating and transporting excavated quantities.
It is previously known to arrange an excavating machine on pontoons for carrying out excavation work in areas of shallow water. With such pontoon arrangements there is usually a stability problem when excavation is to be done sideways outside the pontoons. In order to compensate to a certain extent for the tipping tendencies in such excavation it is usual to provide the pontoons with extra buoyant bodies or with supporting legs projecting down to the sea/lake floor for support, or a combination of such arrangements. In spite of taking such measures, the possibilities of utilizing large excavating shovels for taking up comparatively large quantities of earth at each excavating movement are limited. Excavating work on the sea/lake floor is concerned in most cases with moving earth quantities from one place to another, e.g. for dredging a channel for a navigable passage or providing a trench on the floor for a pipeline, cable or the like. It is thus more seldom a question of lifting up earth quantities from the sea/lake floor and dumping these on land. On the other hand, it is desirable to transport such large earth quantities as is possible in each excavating operation, since when working in water it is necessary to expect considerable slipping back of earth quantities in the excavated area, as well as loss of earth quantities during transport under water.
The present invention intends to solve the above-mentioned problem in a simple and effective way. The apparatus comprises a generally simple frame structure, to which there is attached a power shovel apparatus, pivotable in relation to said frame. The frame is built up, per se, of preferably two or more vertically mobile pontoons with sufficient buoyancy for lifting up and transporting earth quantities excavated from the floor.
The invention will now be described while referring to the attached drawing which shows an embodiment of the invention.